Authorities believe the suspect wore two disguises in carrying out his heists - one entailing a piece of cloth worn over his head with eye holes cut out, and one consisting of a tight-fitting metallic-looking mask.

Initially, investigators thought the robberies were the work of two individuals, dubbing them the "Elephant Man Bandit" and "Cyborg Bandit."

But similarities led them to consider that one person was behind all the heists, according to FBI spokeswoman Ayn Sandalo Dietrich.

The suspect always wore latex gloves, he never brandished a weapon and he hit banks in a two-county area.

"It took a lot of tiny pieces of information that came from the different robberies," Sandalo Dietrich added. "Pulling them all together is what enabled us to build the investigation."